590, 14 inch with Vang Comp, with some longer barrels for other purposes. Bead Sight with XS big dot on the short barrel. I'd run a hogue short stock instead of the speedfeed on mine though, and a decent sling.
S&W model 65 3" round butt (or Model 13).
Small enough to conceal easily, big enough to shoot well, .357 magnum so it can be loaded to deal with medium game, or shoot .38 wadcutters for practice.
Neither are super tactical, or cool guy, but they cover all my bases.
If I could grab a third, it would be a S&W Model 63 or 34 with a short barrel. Deep Concealment J-frame, .22 LR for all .22 does.
ETA:
I generally prefer Stainless, or Marinecoat for the longevity, but blued is fine too.
ETAx2:
If we are going off of guns that I personally own...
Mossberg 500 18.5 Marinecoat, XS big dot, sidesaddle, sling, light, and hogue short stock
S&W Model 686-1 4", Ahrends Grips.